The isolation of specific molecular moities is often a necessary step in the process of preparing assay tests for various compounds, particularly in the field of medicine. Such target moieties as enzymes, antibodies and the like are routinely employed in such assays. For example, if a particular chemical moiety such as human growth hormone ("HGH") is to be assayed, the appropriate assay reagent may employ an antibody to the HGH and to which the HGH becomes attached during the assay procedure. Assays of this type are well known to the art, and need not be described further. Reference may be made to Maggio, et al, U.S. Pat. No. 4,233,402, Adams, et al, U.S. Pat. No. 4,039,652 and Murray, et al, U.S. Pat. No. 4,307,071. The antibody and the HGH hence form members of a specific binding pair consisting of the antibody and the hapten fraction of the HGH. Other specific binding pairs are well known and include hormones and hormone receptors, chemical moieties containing specific carbohydrate groups and lectins, and enzymes and their specific binding partners including cofactors, inhibitors and chemical moities whose reaction the enzymes promote.
Other proposed or current uses of specific binding pair reactions may involve, for example, the uses of antibody-carried poisons or toxins to selectively bind to and kill cancerous cells, and the uses of such reactions in the purification or separation of chemical species.
Although the concept of employing specific binding pairs in various assay procedures and for other uses is well known, it often becomes difficult and hence expensive to select, isolate and bind the specific desired member of the specific binding pair in the preparation of a reagent. The desired binding pair member, commonly a proteinaceous substance such as an antibody, enzyme, etc., often must be selected chemically from a solution containing various other closely related moities. It will be understood that the desired member of a specific binding pair, in many assays of this type, must be bound to other chemical species o to substrates.